GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Imperata contracta

HABIT Perennial. Rhizomes elongated; scaly. Culms erect; 100–200 cm long; 1–2 mm diam. Culm-internodes hollow; distally glabrous. Lateral branches lacking. Leaves basal and cauline. Leaf-sheath auricles erect. Ligule a ciliolate membrane; 0.5–1.5 mm long; brown. Leaf-blades erect; straight; tapering towards tip and sheath; 30–70 cm long; 5–11 mm wide; stiff. Leaf-blade midrib widened. Leaf-blade surface glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle spiciform; linear; tapering above; 25–50 cm long. Primary panicle branches ascending; 2–5 cm long. Panicle axis scabrous; villous. Panicle branches scabrous; villous.

Racemes bearing few fertile spikelets. Rhachis tough; subterete. Rhachis internodes filiform.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels filiform; unequal; 0.5 mm long, or 1.5 mm long; scabrous; villous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; subterete; 2–3.5 mm long; falling entire. Spikelet callus bearded; base truncate. Spikelet callus hairs white; 8–12 mm long.

GLUMES Glumes similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; membranous; without keels; 3 -veined. Lower glume surface smooth, or asperulous; villous. Upper glume lanceolate; 1 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface smooth, or scabrous; villous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to fertile lemma; oblong; 1.5–1.8 mm long; hyaline; 0 -veined; without midvein; without lateral veins; erose; obtuse. Fertile lemma ovate; 0.7–1.1 mm long; hyaline; without keel; 0 -veined. Lemma apex acute. Palea hyaline; 0 -veined; without keels.

FLOWER Lodicules absent. Anthers 1; 1.3–2 mm long. Stigmas 2; terminally exserted.

FRUIT Caryopsis with adherent pericarp; obovoid; 0.7 mm long.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. Fl Costa Rica 1994.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.